First-in-Class Movantik Approved for Opioid-Induced Constipation

Movantik is a peripherally acting mu-opioid receptor antagonist (PAMORA). It is designed to block the binding of opioids to the opioid receptors in the gastrointestinal tract without impacting the opioid receptors in the brain. Movantik was developed using Nektar Therapeutics' oral small molecule polymer conjugate technology.

The safety and efficacy of Movantik were established in two clinical trials of 1,352 patients who had taken opioids ≥4 weeks for non-cancer pain and had opioid-induced constipation. Patients were randomized to Movantik 12.5mg or 25mg or placebo once daily for 12 weeks. Results of one trial showed that 44% of patients receiving Movantik 25mg and 41% of patients receiving Movantik 12.5mg experienced an in crease in bowel movements per week vs. 29% of patients taking placebo.

Movantik is currently classified as a Schedule CII controlled substance because it is structurally related to noroxymorphone. A postmarketing study is being required to further study the potential risk of cardiovascular adverse events in patients taking Movantik. Movantik is expected to launch in the first half of 2015.